Device for automatically adjusting slides or tables or the like



Jan. 17, 1967 H. E. PFEIFFER 3,298,255

DEVICE FOR AUTOMATICALLY ADJUSTING SLIDES 0R TABLES OR THE LIKE FiledAug. 28, 1964 5 Sheets-Sheet 1 Jan. 17, 1967 H. E. PFEIFFER 3,298,255

DEVICE F0 UTOMATICALLY USTING SLIDES TABLES OR TH IKE Filed Aug. 28,1964 3 Sheets-Sheet 2 Jan. 17, 1967 H. E. PFEIFFER 3,293,255

' DEVICE FOR AUTOMATICALLY ADJUSTING SLIDES OR TABLES OR THE LIKE FiledAug. 28, 1964 I5 Sheets-Sheet 3 United States Patent 10,792/63 4 Claims.01. 77-64) The invention relates to a device for automatically adjustingslides or tables or the like, more particularly coordinate tables, ofmachine tools, through the agency of cams determining the position inwhich the slides or the like are set up.

It is an object of the invention to enable a large number of positionsassociated with the lengthwise and transverse movements of an adjustableslide or the like to be stored in readily adjustable and repeatablefashion, for instance, so that drilling machines can drill workpieceshaving a large number of bores in series without the use of templates orjigs or the like.

Devices of this kind are known, but in most of them the control cams aredisposed in a single plane in adjacent grooves, with the result that thelimited space means that only a relatively small number of grooves canbe provided.

According to the invention, the cams are disposed on the periphery ofcontrol drums in driving engagement with the slides or the like.Preferably, the cams are dis posed on the outer periphery of clampingrings which clamp automatically on the drum.

For a better understanding of the invention and to show how the same maybe carried into effect, reference may now be made to the accompanyingdrawings where- FIGURE 1 is a diagrammatic side elevation of acoordinate table having two control drums;

FIGURE 2 is a plan view of the table shown in FIG- URE 1;

FIGURE 3 is a cross-section through a control drum, the detector and thesetting pin;

FIGURE 4 is a section taken along the line IVIV of FIGURE 3, and

FIGURE 5 is a longitudinal section through a control drum.

A WOIk table 3 shown in FIGURES 1 and 2 has in known manner a base 1 onwhich a cross-slide 2 is mounted in readily movable manner, forinstance, by means of anti-friction bearings; an electric motor (notshown) can move the slide 2 in a direction y. The table 3 is so mountedon the slide 2, for instance, via antifriction bearings, as to bemovable in a direction x by means of an electric motor (not shown). Theslides 2 and 3 can be operated by motor drive units controlled bycontrol switches in a simple control circuit as shown in United StatesPatent 2,648,237 issued August 11, 1953. One end of each of two steelbands 4a, 4b is secured to the table 3; their other ends are rigidlysecured to the cylindrical periphery of a drum 5 which is mounted on theslide 2 and which is connected via a shaft 6 to a control drum Wx. Thedrum Wx rotates through slightly less than 360 for a movement of thetable 3 over the whole of its travel. Also mounted on the slide 2 is adrum 7 whose axis is perpendicular to the drum 5. The drum 7 has acylindrical periphery; secured thereto are the ends of two steel bands8a, 8b whose other ends are rigidly secured to the base 1. Consequently,when the slide 2 performs the whole of its travel in the y direction,the drum 7 rotates through less than 360. This rotation is transmittedby two face gears 9 to a shaft 10 having a control drum Wy secured toits end. The two drums Wx, Wy are therefore disposed one beside anotherand have their axes parallel with one another. Special means which donot form part of this invention and which are therefore not describedensure that the movements of the slide 2 and table 3 are transmittedwithout backlash to the drums Wx, Wy.

The two drums Wx, Wy are of basically similar construction, and so onlythe drum Wx is shown in FIG- URES 3-5. As is diagrammatically shown inFIGURES 3 and 4, a number of clamping rings 11 are clamped fast to thedrum Wx and have sufficient clamping action on their own not to bedislodge on the drum surface by forces produced by the detectorelements. The clamping rings 11 each have two inclined surfaces 12 whichserve as cams, are disposed exactly 180 opposite one another and formtransition surfaces between a raised part 11b and a recessed part 11a ofthe periphery of the rings 11. A detector 13 detects the periphery ofeach ring 11 and co-operates with electric switches 14, 15 controllingthe motor operating the table 3. All that will be mentioned here is thatthe table 3 is stopped and secured in the dead correct position wheneverapex 13a of the detector 13 is in the centre of the cam 12.

Each ring 11 is formed with a through radial slot 16 which widensradially outwards wedge-fashion, and the slots 16 are disposed in aplane E which is offset by an angle oc= from the horizontal plane Epassing through the centres of the earns 12. A support member 17 whichis disposed above and extends along the drum Wx has passages 18 alldisposed in the plane E The spacing between the passages corresponds tothe spacing between the individual rings 11; as can be seen in FIG- URE5, in actual practice the spacing is determined by spacer rings. Thepassages 18 are adapted to receive pins 19 having a wedge-shaped end 20whose wedge angle is the same as the wedge angle of the slot 1%.

To re-set a ring 11 in order to store a new table position, theelectrical detecting and drive system is first started to bring thetable into the position determined by the particular ring 11 concerned,such position being shown in FIGURE 3, whereafter a pin 19 is introducedinto the passage 18 and pressed. right home so that the ring 11 isexpanded and becomes a loose fit on the drum Wx. The table 3 is thenmoved into the new position and carefully adjusted, whereafter the pin19 is removed so that the ring 11 clamps the drum Wx tightly again tomemorise the new position of the table. The table can be returned tothis new position whenever required by automatic detection. The slide 2can be controlled by the drum Wy in just the same way.

A practical form of the drum Wx is shown in FIGURE 5. As will beapparent therefrom, t-wo clamping rings 11 are disposed below eachpassage 18 in order that a very large number of clamping rings may beprovided for a given length of the drum Wx. In this case, the pins 19have a wedge-shaped portion 20 extending over only half theircrossasection so that they can expand either one ring 11 or the other intwo positions apart from one another. The support member 17 has twobearings 21 for the drum Wx. In order that the rings 11 may he slid on,one end of the drum is conical and has a head 22 which is secured to thedrum Wx by screws 23. The head 22 is formed with a groove 26 engaged bya plate 24 providing axial location of the whole drum Wx. A spring strip24a which can be loaded by a nut 25 also engages in the groove 26 toenable the drum Wx to be clamped fast with the support member 17.

The drum Wx is driven by shaft 6 via a sleeve 27 and collet chuck 28. Acup spring 31 presses the jaws 30 of the chuck 28 against a cylindricalinside surface 29 of the drum Wx and is in turn loaded via a sleeve 32by a loading screw 33, so that its periphery is increased and it forcesthe jaws 30 against the surface 29.

The device hereinbefore described can provide a neutral movement. Whenthe rings 11 have been set up to a particular programme, for instance, adrilling pattern, but the workpiece chucked on the table 3 is still inthe wrong position relatively to the drum Wx, the table 3 can beaccurately adjusted, either by hand or by means of an optical adjustingsystem, relatively to the co-ordinates of the first drilling operationonce the nut 25 has been tightened and the screw 33 slackened. Duringthis a-djustment'the drum Wx moves relatively to its drive shaft 6. Oncethe adjustment has been made, the screw 33 is re-tightened and the nut25 slackened. The drum Wx is then correctly positioned relatively to theworkpiece.

What I claim is:

1. In a device for automatically controlling the movement of motoroperated cross slides having an electric control switch in a motorcontrol circuit comprising a support, rotatable drum means mounted insaid support, means drivingly connecting one cross slide to the drum forrotation in said support, a series of split rings clampingly mounted onsaid drum to rotate therewith, cam projections on each of said rings toactuate the electric control switch during rotation of said drum, aseries of guide openings in said support arranged in radial alignmentwith said rings, a pin selectively mounted in at least one of saidopenings with its inner end presented to said rings, whereby said drummeans may be moved into registry with the split portion of one of saidrings and forced inwardly to expand a selected ring and release itsclamping action on said drum, said pin also arresting movement of theselected ring While the drum is moved to various positions.

2. In a device as set forth in claim 1 in which the split portion ofeach of said rings forms a slot having outwardly and radially inclinedsurfaces forming a V-shaped through notch and in :which the end of thepin is correspondingly shaped to expand the ring selected and releaseits gripping action on the drum.

3. In a device as set forth in claim 1 in which two control drums areprovided, one for each slide and in which the means for drivinglyconnecting the slides to the drums includes a coll-et chuck forconnecting the drums to their respective drive means, and the chuck jawsare adapted to be expanded by a cup-shaped spring which is screw loadedand in which means are provided to clamp each control drum in a fixedposition relative to said support so that the work table or slide can beadjusted relatively to either control drum for a predetermined workprogram set up by preselecting the positions of certain clamping rings.7

4. In a device as set forth in claim 1 in which the cross slidesembodies a slide and a coordinate cross work table slide, and in whichthe drum means comprises a pair of drums in which the means fordrivingly connecting the slides to the drums includes flexible strapsfor converting sliding movement of the slides to rotational movement ofthe drums. 1

References Cited by the Examiner FRANCIS S. HUSA'R, Primary Examiner.

1. IN A DEVICE FOR AUTOMATICALLY CONTROLLING THE MOVEMENT OF MOTOROPERATED CROSS SLIDES HAVING AN ELECTRIC CONTROL SWITCH IN A MOTORCONTROL CIRCUIT COMPRISING A SUPPORT, ROTATABLE DRUM MEANS MOUNTED INSAID SUPPORT, MEANS DRIVINGLY CONNECTING ONE CROSS SLIDE TO THE DRUM FORROTATION IN SAID SUPPORT, A SERIES OF SPLIT RINGS CLAMPINGLY MOUNTED ONSAID DRUM TO ROTATE THEREWITH, CAM PROJECTIONS ON EACH OF SAID RINGS TOACTUATE THE ELECTRIC CONTROL SWITCH DURING ROTATION OF SAID DRUM, ASERIES OF GUIDE OPENINGS IN SAID SUPPORT ARRANGED IN RADIAL ALIGNMENTWITH SAID RINGS, A PIN SELECTIVELY MOUNTED IN AT LEAST ONE OF SAIDOPENINGS WITH ITS INNER END PRESENTED TO SAID RINGS, WHEREBY SAID DRUMMEANS MAY BE MOVED INTO REGISTRY WITH THE SPLIT PORTION OF ONE OF SAIDRINGS AND FORCED INWARDLY TO EXPAND A SELECTED RING AND RELEASE ITSCLAMPING ACTION ON SAID DRUM, SAID PIN ALSO ARRESTING MOVEMENT OF THESELECTED RING WHILE THE DRUM IS MOVED TO VARIOUS POSITIONS.